From 4cd34e7c2e412e3db2f6bf7371581ab60591174b Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 31 Aug 2018 10:00:02 -0400 Subject: [PATCH] SUNRPC: Simplify dealing with aborted partially transmitted messages If the previous message was only partially transmitted, we need to close the socket in order to avoid corruption of the message stream. To do so, we currently hijack the unlocking of the socket in order to schedule the close. Now that we track the message offset in the socket state, we can move that kind of checking out of the socket lock code, which is needed to allow messages to remain queued after dropping the socket lock. Signed-off-by: Trond Myklebust --- net/sunrpc/xprtsock.c | 51 +++++++++++++++++++++---------------------- 1 file changed, 25 insertions(+), 26 deletions(-) diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 629cc45e1e6c..3fbccebd0b10 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -491,6 +491,16 @@ static int xs_nospace(struct rpc_task *task) return ret; } +/* + * Determine if the previous message in the stream was aborted before it + * could complete transmission. + */ +static bool +xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req) +{ + return transport->xmit.offset != 0 && req->rq_bytes_sent == 0; +} + /* * Construct a stream transport record marker in @buf. */ @@ -522,6 +532,12 @@ static int xs_local_send_request(struct rpc_task *task) int status; int sent = 0; + /* Close the stream if the previous transmission was incomplete */ + if (xs_send_request_was_aborted(transport, req)) { + xs_close(xprt); + return -ENOTCONN; + } + xs_encode_stream_record_marker(&req->rq_snd_buf); xs_pktdump("packet data:", @@ -665,6 +681,13 @@ static int xs_tcp_send_request(struct rpc_task *task) int status; int sent; + /* Close the stream if the previous transmission was incomplete */ + if (xs_send_request_was_aborted(transport, req)) { + if (transport->sock != NULL) + kernel_sock_shutdown(transport->sock, SHUT_RDWR); + return -ENOTCONN; + } + xs_encode_stream_record_marker(&req->rq_snd_buf); xs_pktdump("packet data:", @@ -755,30 +778,6 @@ static int xs_tcp_send_request(struct rpc_task *task) return status; } -/** - * xs_tcp_release_xprt - clean up after a tcp transmission - * @xprt: transport - * @task: rpc task - * - * This cleans up if an error causes us to abort the transmission of a request. - * In this case, the socket may need to be reset in order to avoid confusing - * the server. - */ -static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) -{ - struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt); - - if (task != xprt->snd_task) - return; - if (task == NULL) - goto out_release; - if (transport->xmit.offset == 0 || !xprt_connected(xprt)) - goto out_release; - set_bit(XPRT_CLOSE_WAIT, &xprt->state); -out_release: - xprt_release_xprt(xprt, task); -} - static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk) { transport->old_data_ready = sk->sk_data_ready; @@ -2764,7 +2763,7 @@ static void bc_destroy(struct rpc_xprt *xprt) static const struct rpc_xprt_ops xs_local_ops = { .reserve_xprt = xprt_reserve_xprt, - .release_xprt = xs_tcp_release_xprt, + .release_xprt = xprt_release_xprt, .alloc_slot = xprt_alloc_slot, .free_slot = xprt_free_slot, .rpcbind = xs_local_rpcbind, @@ -2806,7 +2805,7 @@ static const struct rpc_xprt_ops xs_udp_ops = { static const struct rpc_xprt_ops xs_tcp_ops = { .reserve_xprt = xprt_reserve_xprt, - .release_xprt = xs_tcp_release_xprt, + .release_xprt = xprt_release_xprt, .alloc_slot = xprt_lock_and_alloc_slot, .free_slot = xprt_free_slot, .rpcbind = rpcb_getport_async, -- 2.30.2